ES2594609T3 - Separation procedure of a synthetic grass product - Google Patents

Abstract

A method of separating a dry or dried synthetic turf product comprising at least one support material, a grass fiber component and additional components, said process comprising at least the consecutive steps of (a) reducing the size of the product of synthetic grass to a grass material reduced in size; (b) separating the grass material reduced in size by screening it to give at least a first fraction comprising substantially a mixture of support material and additional components and a second fraction comprising substantially grass fiber components; (c) separating the first fraction obtained in step (b) by specific weight using air to provide a low density fraction comprising substantially support material and a high density fraction comprising substantially additional components; (d) separating the second fraction obtained in step (b) by specific weight and size by providing an upward directed air flow in a separator configured to cause a swirling movement by means of which the lighter fraction is dragged up in the air flow and the heavy fraction is dropped down; wherein the lighter fraction substantially comprises grass fiber components and the heavy fraction substantially comprises a mixture of support material and additional components; and (e) collect the low density fraction obtained in step (c) and the light fraction obtained in step (d).

Description

DESCRIPTION

Separation procedure of a synthetic grass product

The present invention relates to an improved process for recovering the individual components of a synthetic or artificial turf product in a manner almost similar to its original initial state. The result is achieved by a procedure in which the grass is submitted after reducing its size to at least three specific separation stages in a specific order, based on the separation in size, specific weight and specific weight, size and shape.

Background

Synthetic grass has been used for many years as a surface for football, baseball and soccer fields. In recent years it has been used in other applications where an alternative to natural grass is desired. These applications include at least playgrounds, residential and commercial meadows and other gardens, roads, paintball paintball fields, tennis courts, golf courses, dog racing tracks, etc.

Normally, synthetic grass includes a weave-like fabric that has a support and a plurality of vertical ribbons, also called outer fibers, that resemble grass. Many synthetic turf products 15 also include a filler material dispersed between the vertical belts, which may consist of sand, rubber tire chips or other particles, either individually or in combination with each other. The filling material simulates the soil of the natural grass, acts as a ballast and / or contributes to the physical properties of the grass, such as resilience, which makes the grass suitable for a particular use. twenty

Synthetic grass has a limited lifespan, which depends on the construction of the lawn, the application for which it is used, the weather conditions and how the lawn is maintained.

For example, a typical synthetic lawn that is used as a sports field can have a lifespan of approximately 8 to 15 years. A large number of synthetic lawns are currently used in hundreds of sports fields and in other applications. 25

Lawn removal is very expensive due to the composition of materials that vary from recycled rubber, sand to plastic. To avoid sending the grass to the landfill at a substantial cost, recycling and reuse of all synthetic grass or portions thereof has been an option explored in recent years.

The procedures for recycling carpets and for preparing carpet supports using remnants of 30 recycled carpets are known. Some of these procedures involve the separation of threads from carpets, or tufts, from the support, for example by cutting and processing only threads.

However, synthetic grass differs in carpet composition and these differences in composition make conventional carpet recycling procedures unsuitable for recycling synthetic grass. Most carpet products use outer nylon fibers, while most of today's synthetic turf products use polyethylene.

The primary coating of most carpets is a latex coating, while the coating of most synthetic lawns is polyurethane. In the United States, only a small fraction of roll carpets includes a polyurethane-containing coating and only a small fraction of synthetic lawns has a latex-containing coating. 40

Most of the synthetic lawns manufactured in the last 6 years have had a polyurethane coating applied to the support. It is believed that synthetic grass coated with polyurethane cannot be recycled as a whole. This is because the polyurethane coating cannot be recycled effectively. Polyurethane is thermosetting (unlike thermoplastic) and is therefore difficult and expensive to recycle. Four. Five

However, the recovery of polyurethane from carpets is described in US 5,185,380 in which the support is scraped off, crushed, subjected to a cyclone sorting step to remove hard foreign constituents, such as Metals and PVC and non-hard constituents are consolidated at elevated pressure and temperature to provide sheets. This procedure thus provides a new product from portions of the carpet used. fifty

On the lawn, the coating is applied to the support of a tufted material in order to fix the outer fibers to the primary support. An additional coating of a hot melt adhesive or a polyurethane foam can also be applied. This secondary coating is normally used to join a secondary support that can be polyester or polypropylene.

Many synthetic grass products include components that are not found in carpets and that are incompatible with, or at least undesirable in, conventional carpet recycling procedures. For example, conventional carpet does not include padding. Fillers for synthetic turf installations include sand, rubber tire shavings and / or other particulate materials, either individually or in combination with each other. Thus, the recycling of synthetic grass presents a unique problem that is not found in the recycling of carpets.

Separating the landfill from the rest of the lawn may require the use of special equipment and there may be environmental problems associated with the removal of the separate landfill. Other problems in the recycling process are the effect of any residual filler particulate material in the size reduction process and in the properties of the final product. 10

Thus, attempts have been made to recycle and reuse an existing synthetic turf, or at least a portion of an existing synthetic turf, to avoid sending all of the synthetic turf to a landfill when it is no longer useful. Such a procedure is described in WO 2010/075098 in which the filling is separated from the support and the grass-like fibers, followed by the reduction in size and subsequent removal of the filling followed by agglomeration. Agglomerated grass fragment granules are arranged in an extruder. The granules are extruded to form an extruded material, for example in the form of a strip or a tape.

Most of the known processes therefore recycle the constituents of carpets or lawns to give new products of mixed components and do not apply reverse engineering to the products to obtain the individual starting components. twenty

EP 2096211 A2 provides a method for discarding synthetic grass, for example by dividing the entire synthetic grass, for example grass and padding followed by separation of carpet grass and synthetic grass filaments. A similar separation of grass and landfill is shown in EP 2186942 A1 for the purpose of recycling cargo material. In document KR 20130106053 A the filling material is removed and the grass fiber component is cut in the carpet 25 while keeping the carpet intact.

Thus, existing procedures can separate the materials to a purity of 95% which is only satisfactory when, for example, the procedure is to extrude / consolidate to provide new products. Thus, while prior art procedures are an improvement over disposal of material in the landfill, there is still a need to separate the individual parts additionally, into 30 fractions that substantially comprise a component in order to provide products of improved quality. .

It is also desirable to provide procedures that are flexible, since the composition of the lawn and the landfill may vary.

It is also desirable to provide processes in which the result is the purified individual components at a level that is high enough to be reused as turf or in other industries.

Therefore, the object of the invention is to provide an improved method for separating constituents of various lawn products and also to provide a process where the purity of each of the separated constituents varies from more than 95% (w / w) to be essentially pure. 40

Summary of the invention

In a first aspect, this and other objects are solved by a method in which a substantially dry synthetic turf product is provided comprising at least one support material, a grass fiber component and additional components and in which said process comprises at least the 45 consecutive stages

(a) reduce the size of the synthetic grass product to a grass material reduced in size;

(b) separating the grass material reduced in size by screening in at least a first fraction comprising substantially a mixture of support material and additional components and a second fraction comprising substantially grass fiber components; in which the procedure additionally comprises 50

(c) separating the first fraction obtained in step (b) by specific weight using air in a low density fraction comprising substantially support material and a high density fraction comprising substantially additional components;

(d) separate the second fraction obtained in step (b) by specific weight, size and shape by providing

an air flow directed upwards in a separator configured to cause a swirling movement by means of which the lighter fraction is dragged up in the air flow and the heavy fraction is dropped down, where the lighter fraction comprises substantially grass fiber components and the heavy fraction substantially comprise a mixture of support material and additional components; and 5

(e) collect the low density fraction obtained in step (c) and the lightest fraction obtained in step (d).

The complete separation of components from used turf products has proven to be a very difficult task. The problem arises with the separation in particular of the last 5% of the other constituents in the various fractions. During the size reduction, which is necessary to make the grass product 10 manageable, the individual components are mixed additionally and more homogeneously and therefore are more difficult to separate. Essentially complete separation is necessary so that the various fractions can be reused in a high quality final product.

The sequence and the specific mode of separation of the individual components, that is to say by simple screening by size, separation by specific screening, that is by specific weight, and / or by separation by air swirling, that is by specific weight , size and shape, has proved to be key to ultimately achieve complete separation.

In the first stage of size reduction the support material and the grass fiber components are the main objective. Most of the additional components, such as earth, are presented in a reduced size. twenty

In the first stage of separation the components are separated only by size. Since the product has been reduced in size, this stage will separate most of the components of the grass fiber component. Therefore, components that have densities that are more similar have been separated and subsequent reduction of the size may be possible, if desired.

After the first separation stage the first fraction comprising substantially support material is further separated by specific weight using air. By this means the lighter components are fluidized and separated from the heavy components. This will separate the support material from the additional components, so that the support material, being lighter than the ground, etc., is isolated as the low density fraction.

Suitable separation means include, but are not limited to, separating tables available from Trenn-30 und Sortiertechnik GmbH and Guidetti S-r-l., Renazzo, Italy.

The second fraction of the first separation is separated by specific weight, size and shape in an operational stage. This separation is obtained by providing an air flow that produces a swirling movement directed upwards in a separator through which the lighter fraction is dragged up in the air flow and the heavy fraction is dropped down; the lighter fraction comprises substantially grass fiber components and the heavy fraction substantially comprises a mixture of support material and additional components.

The separator used for separation can be any means suitable in the art such as a cyclone separator, for example, Hovex De-Sanding Cyclone of Gea AG, a zig-zag air sweep screener, for example sweeping screener. ZZS air from Trenn- und Sortiertechnik GmbH, or similar separation media.

In specific embodiments the screening of stage (b) is performed in a plurality of sets of sieves and / or the separation by specific weight of stage (c) is performed in a plurality of sets of separators and / or where the separation of step (d) is performed in a plurality of sets of separators. Four. Five

It is contemplated that the plurality of sieve assemblies, etc., may be arranged in series and / or in parallel. When they are in parallel, the capacity of the separation process can be increased while the serial arrangement is a means to increase the yield without compromising the purity of each of the fractions for reuse.

In preferred embodiments the sieves are drum sieves having apertures of 4-10 mm, such as 50 4, 4.5, 5 or 5.5 and more preferably 5 mm.

It is also contemplated that when one or more sieves are arranged in series in for example stage b, an intermediate size reduction stage can be included therebetween. This ensures that a larger proportion of the material reduced in size has obtained the largest desired dimension and at the same time the fraction of grass fiber will contain less of the other components present.

originally. It is contemplated that when one or more sieves are present they have the same size or different sizes. In one embodiment the first stage of size reduction is about 50 mm and the second stage of size reduction is about 30 mm and in additional embodiments the sieves have a mesh size of 6-8 mm, preferably 5 mm.

In a further embodiment, the additional components comprise a filler and the first fraction 5 obtained in step (b) before step (c) is subjected to an intermediate screening step (i) to provide a third fraction comprising substantially material of support and a fourth fraction comprising substantially filler and in which the third fraction comprising substantially support material is further processed in step (c) and the fraction comprising substantially filler is recovered. 10

In a particular embodiment, the filler material comprises sand and rubber and the fourth fraction obtained in step (i) is subjected to the additional step (f) of separating by specific weight to provide a low density fraction comprising substantially rubber and a high density fraction that substantially comprises sand. After this separation stage, the rubber fraction and the sand fractions, respectively, are essentially pure. fifteen

Usually when the grass product comes from a sports field, rubber and / or sand are used as fillers. While a large proportion of the sand and rubber can be easily separated from the remaining part of the turf product, substantial amounts of sand and rubber are still present within the structure. In particular, sand, earth or gravel can be removed from the polymer components to improve their applicability in the same product (i.e. artificial grass) or other types of products. twenty

Being able to provide the essentially pure rubber fraction is necessary for the reuse of the same in the same application. The purity of the rubber fraction can be determined by standard tests as described below.

In a further embodiment, the intermediate separation step (i) is carried out by screening through a plurality of sieves, preferably integrated in a unit, where at least a first sieve has a mesh size of 3 mm; and at least a second sieve has a mesh size of 0.8 mm; said separation provides a large fraction where the length of the largest dimension of the material reduced in size is 3 mm or greater, said large fraction comprising substantially grass fiber components; an intermediate fraction where the length of the largest dimension of the material reduced in size is in the range of 0.8 to 3 mm and which comprises said substantially material intermediate intermediate of support; and a small fraction in which the length of the largest dimension is 0.8 mm or less, said small fraction substantially filled.

In this embodiment the large fraction is mixed with the second fraction obtained in step (b) before being further separated in step (d). The intermediate fraction is provided in step (c) and the small fraction is provided in step (f). Including this separation stage, the yield of each fraction can be increased.

According to the process of the invention, the second fraction obtained in step (b) is reduced in size in a preferred embodiment further before being separated in step (d), for example in a cutting mill, preferably to a size where the Length of the largest dimension of the material reduced in size is approximately 7 to 9 mm, more preferably 8 mm. 40

As indicated above, the separation task becomes more and more difficult when the size of the mixed components becomes smaller and smaller. Thus, as the smallest size becomes the difference in weight of the individual components approximates. On the other hand the reduction of size is a necessary means to be able to disintegrate the diverse components of the material of grass.

Therefore, the reduction in size at these specific points of separation has proven effective, since otherwise problematic components have been substantially separated in the previous stages.

In another preferred embodiment, the separation of the step (d) is carried out in a zigzag air screener.

This will provide a separation where the most homogeneous, now very small particles are separated by specific size, shape and weight and in which the swirling movement is provided by structures 50 inside the separator. This facilitates the enrichment of the grass fiber components.

In still a preferred embodiment, the separation of step (d) is performed by supplying air in the separator at a frequency of 18-27 Hz, more preferably 20-25 Hz and most preferably 25 Hz. And in one embodiment The separation is preferably carried out in a zig-zag screener at the above 55 air frequencies.

Tests were carried out with various frequencies above and below the previous intervals and it was surprisingly found that the best separation was obtained within the disclosed intervals and the best result was obtained at 25 Hz.

In an even more preferred embodiment, the separation and swirling movement is carried out in two stages, in which the air frequency of the first stage is greater than the frequency in the second stage. 5 In a further embodiment, the frequency was approximately 25 Hz in the first stage and approximately 20 Hz in the second stage. This combination results in a fraction of grass that was essentially pure.

In preferred embodiments, the starting material is dried so that it is substantially free of water. Drying is important in the separation stages where the separation is partially or totally based on the weight of the components. Drying is within the capacity of the technique. The process of the invention is preferably a completely dry process. Most preferably, the turf product is dried before stage (a) or between stages (a) and (b).

It is also contemplated that magnets are inserted at various points of the process to remove magnetic components or contaminants and preferably, the magnets are located before the cutting stages using a cutting mill to prevent the destruction of the blades.

In a second aspect a system is provided to separate synthetic or artificial turf product, the system being configured as detailed above.

The order of the separation stages and in additional embodiments the parameters of the separation stages is key to the procedure and the system. Separation orders, combination of 20 separations and different parameters result in a final product of lower quality, that is fractions comprising substantial amounts of other constituents and / or contaminants, which makes the fraction less usable as a high recycling product quality.

All embodiments and variations described with reference to the procedure apply equally to the system. 25

In another aspect, the invention provides recycled components of an artificial turf product and more specifically, recycled sand, recycled rubber, recycled grass fiber components and recycled support material.

The products are characterized by a purity of more than 95% (w / w) of the fraction. Even more preferably, more than 96% (w / w), more than 97% (w / w), more than 98% (w / w), more than 99% (w / w), or about 100% of the fraction.

Lawn products often comprise components of different colors, so the resulting fractions can be visually evaluated to assess purity.

The purity of eg rubber can be evaluated using standard tests in the art, such as ASTM International D5603 to analyze the purity of rubber. 35

The products or fractions obtained by the process of the invention are useful as starting materials in a number of industries such as but not limited to the rubber molding industry, the construction industry, the synthetic grass industry and the extrusion industry. of plastic.

Therefore, in another aspect the invention can be seen as a process for providing a starting material in the manufacture of rubber tiles, rubber mats, rubber floors, plastic pellets and plastic boxes; in which the procedure comprises the steps and variations indicated above.

Figures

Figure 1 is an illustration of the process of the invention in which the synthetic grass product does not comprise a fill. Four. Five

Figure 2 is an embodiment of the process of the invention in which the synthetic grass product comprises a sand and rubber filler.

Detailed description

In the context of the present invention, essentially pure means that a component comprises more than 95% (w / w) of the fraction. Even more preferably more than 96% (w / w), more than 97% (w / w), more than 98% 50 (w / w), more than 99% (w / w), or about 100%.

In the context of the present invention, substantially pure means that more than half (w / w) of the fraction comprises a specific component.

As used in the present invention, the term "a component" means a type of chemical composition of the starting product, such as sand, rubber, polyethylene (PE), etc. The expression should not be limited to the component that originates from a specific part of the turf material but rather is defined by its type of chemical composition.

As used in the present invention, the term "synthetic grass product" contemplates all components of the starting material used in the process of the invention. Synthetic and artificial can be used interchangeably and have the same meaning, namely a product similar to the herb made of non-biological material. 10

The starting material for the process of the invention is a lawn product from a sports facility, a playground, a garden area and the like. The origin of the material should not be limited. It is also contemplated that the material may comprise contaminants.

The synthetic grass product usually comprises at least one support material and a grass fiber component. fifteen

In the context of the present invention, the term "support material" contemplates one or more layers to support the grass fiber component. Thus, the term support material includes, but is not limited to, a material in which an artificial grass fiber is tufted, knitted or knitted, or otherwise bonded. The term "support material" also contemplates a secondary support or covering or fixing parts for attaching pieces of grass products to each other or to a surface. twenty

In the context of the present invention, the term "grass fiber component" contemplates fibers or threads, textured or textured, arranged in tufts, knitted or knitted or otherwise bonded to the support material.

In the context of the present invention the expression "additional components" contemplates any material included in the turf product not included in the terms "support material" and "grass fiber component". Thus, the additional components may comprise, but are not limited to, filler, waste materials trapped in the carpet of the grass, soil, sand, etc.

The synthetic turf product may also comprise roofing straw or a "roofing straw area" comprised of one or more roofing straw materials, preferably connected to the support material in a manner such as interlacing, gluing, melting or any Suitable medium for joining 30 roofing straw materials to the support material. The application of roofing straw to synthetic turf is well known in the art and is described in various documents, such as US 6,299,959 and WO 2004/042149. In the context of the present invention, the material constituting the roofing straw, the area of roofing straw and / or the application of roofing straw is included in the expression "grass fiber material". 35

Normally, a synthetic turf product includes a fabric that is a support and a plurality of vertical ribbons, also called outer fibers or threads, that resemble the grass and in the context of the present invention outer fibers or threads are examples of components of grass fibers according to the invention.

Normally, the grass fiber component is made of polyethylene, polypropylene or a mixture thereof. The grass fiber can also be made of nylon or any other material known in the art alone or in combination with polypropylene and / or polyethylene.

These grass fiber components are usually tufted or sewn on a primary support material that can be made of different materials that include, but are not limited to, polypropylene or polyester. Four. Five

A coating material can be applied to the grass fiber and the primary support to keep the grass-like fibers in position.

The primary coating of most synthetic turf products includes polyurethane and also normally includes a coating load such as calcium carbonate or fly ash. Primary coatings may also include latex, hot melt adhesives and / or thermoplastics in addition to or instead of polyurethane.

Synthetic grass products can also have a secondary support or coating that can be made of a number of different materials that include, but are not limited to, polypropylene or polyester.

The grass fiber components normally constitute from about 19% by weight to about 80% by weight of a synthetic grass product. The primary support normally constitutes from about 1% by weight to about 25% by weight of the synthetic grass. The primary coating normally constitutes from about 15% by weight to about 80% by weight of a synthetic turf however other compositions are contemplated. 5

Grass fiber components may include polyethylene, polypropylene, nylon or other materials individually or in combination.

In some embodiments, the grass fibers include mixtures of polypropylene (PP) and polyethylene (PE). In further embodiments, the grass fibers include mixtures of PE or mixtures of PP, PE and nylon.

The primary support may include polyester, polypropylene and other materials individually, or in combination, such as mixtures of PP and polyester.

The coating may include polyurethane, latex, hot melt adhesive and / or thermoplastic materials alone or in combination. Hot melt adhesives include, but are not limited to, Reynolds 54-041, Reynolds 54-854, DHM 4124 (The Reynolds Company P.O. Greenville, SC, DHM Adhesives, Inc. Calhoun, GA). fifteen

Suitable thermoplastics include, but are not limited to, polypropylene, polyethylene and polyester. The coating may also include a coating loading agent that may be fly ash, calcium carbonate, iron oxide or neighborhood sulfate, or any other charge known in the art.

In other embodiments, the synthetic turf product comprises a filler material dispersed between the vertical strips of grass fiber, which contributes to the physical properties of the turf product by making the grass suitable for a specific use.

The synthetic grass fill may be made of any suitable material to provide the desired physical properties, such as but not limited to sand, gravel, cork, coconut shells, polymeric pearls and rubbers, including but not limited to chip rubber, monomer rubber of ethylene propylene ether (EPDM), thermoplastic elastomers (TPE) and neoprene rubber alone, or in combination.

In preferred embodiments, the synthetic turf product further comprises one or more roofing straw materials connected to the support material.

The roofing straw material is usually made of the same material as the grass fiber, polypropylene or nylon component. 30

In a preferred embodiment, the filler material is rubber or sand. In yet another embodiment, the filler material is rubber and sand.

In other embodiments, it is contemplated that the synthetic grass product comprises a padding and one or more roofing straw materials.

When an artificial grass field is removed from the site it is usually cut into 50 x 50 pieces and rolled. The rolls are transported to the site where they will be further processed whether it is a landfill or a facility for product recycling.

The grass field thus split, the grass product, is provided to the process of the invention in rolls that normally have a diameter of 2 to 5 m and a width of 1 to 2 m. The size of the turf product when it reaches the processing facility can be any size and the invention should not be limited by the size of the turf received. The size of the lawn product is limited only by practical handling and the size of the first means of size reduction.

Hereinafter, the embodiments of the process will be described with reference to Figures 1 and 2, which are flowcharts of the process. Variations, examples and details described below can be applied to both embodiments. Four. Five

The process of the invention will now be described in more detail with reference to Figure 1 where the process is illustrated in its most general form for an artificial turf product comprising a support material, a grass fiber component and additional components in form of optional contaminants.

In a first stage, the artificial turf product, 1, is reduced in size in a first cutting stage 50 in a first crusher, A_1, which reduces the size of the turf product to a size of approximately 30 mm, the product of Small grass, 2, is screened through a drum sieve, B_1, which has 5 mm openings, whereby two fractions are provided; a first fraction,

b, which substantially comprises a mixture of support material and additional components where the length of the largest dimension is less than 5 mm and a second fraction, g, which substantially comprises grass fiber components, where the length of the largest dimension is above 5 mm.

After the initial separation, the first and second fractions are further processed independently.

The first fraction, b, which substantially comprises support is further separated by specific weight in a separation medium, C_2, where air is used to fluidize the low density particles by guiding the denser particles to an outlet and the low density particles to A second exit.

The crusher and the screening drum are known components, in general, in the art, the choice of 10 specific units is within the capacity of the technique. The specific crusher used was an H500 / R2-2000 model that can be obtained from Erdwich Zerkleinerungs-Systeme GmbH. The separation medium that can be used to separate by specific weight can be obtained from Trenn- und Sortiertechnik GmbH or from Guidetti S.r.l., Renazzo, Italy.

The second fraction is shown in the reduced size embodiment additionally in a cutting mill, 15 D_1, providing smaller fraction sizes in which the size of the largest dimension is 8 mm; however, it is contemplated that further size reduction may be omitted. After this reduction in size, the second fraction, g, is separated by providing an air flow in a separator, E_1, configured to produce a swirling motion. In the embodiment shown, the separator is a ZZS air sweeping screen that can be obtained from Trenn- und Sortiertechnik GmbH in which the swirling movement is produced by zig-zag channels within the classification channel. The classification provides a lighter fraction, lf, which substantially comprises grass fiber components and a heavier fraction, hf, which substantially comprises additional support and components.

Since the analyzed turf product comprises components of different colors, the resulting fractions were evaluated visually to determine their purity. It seems visually that all fractions have a mainly color.

With reference to Figure 2, an embodiment of the invention will now be described in more detail. In the illustrated embodiment, the artificial turf product in addition to support material and grass fiber components comprises padding in the form of sand and rubber. 30

With reference now to Figure 2, in a first stage the synthetic grass product is reduced in size in a first cutting stage by means of a first crusher, A_1, the length of the largest dimension of the material reduced in size is no more of 50 mm the material reduced in size, 2, is then screened through a first screening drum, B_1, which has perforations of 5 mm, whereby a first fraction is provided, 3, which is larger than 5 mm and a second fraction, 4, which has a size of less than 5 mm. The first fraction, 3, is subjected to a second size reduction stage in a second crusher, A_2, which provides a further reduced material, 5, of no more than 30 mm. The material further reduced in size is screened through a second screening drum, B_2, which also has perforations of 5 mm, thus providing a second fraction, 4_1, which is less than 5 mm in size and a first enriched fraction , 3_1, which has a size 40 greater than 5 mm.

The enriched fraction, 3_1, substantially comprises grass fiber component and the mixed fractions, 4 and 4_1, substantially comprise sand, rubber and support material.

The second fraction, 4 and the second additional fraction, 4_1, are shown in the embodiment subsequently mixed and separated by a plurality of sieves corresponding to step (i). The separation is made in the screening medium, S_1, which has a sieve with a mesh size of 3 mm and a sieve with a mesh size of 0.8 mm. The mixed fractions, 4 and 4_1 are screened through the first screening means, S_1, to provide a large fraction, 3_2, which substantially comprises grass fiber material, an intermediate fraction, 5, which substantially comprises support material and a small fraction, 6, which substantially comprises sand and rubber. fifty

The small fraction, 6, is subsequently separated by specific weight, in a separation medium, C_1, where air is used to fluidize the low density particles by guiding the denser particles to an outlet and the low density particles fluidized to a second output to provide a first heavy fraction, 7_1, which essentially comprises sand and a first light fraction, 8_1, which essentially comprises rubber. 55

The intermediate fraction, 5, is further separated by specific weight, in a separation medium, C_2, in which air is used to fluidize the low density particles by guiding the denser particles to a

outlet and fluidized low density particles to a second outlet to provide a second heavy fraction, 7_2, essentially comprising sand and rubber and a second light fraction, 8_2, essentially comprising support material, sand and rubber.

The second heavy fraction, 7_2, can be further enriched or discarded, as desired, to increase yield. 5

In the example shown, the separators C_1 and C_2 were separating tables TTS No. TTSS900 / 1000/1 and TTS600 / 1000/1 which can be obtained from Trenn- und Sortiertechnik GmbH.

The second light fraction, 8_2, is then separated by sieving on a second sieve, S_2, which has a mesh diameter of 1.0 mm. The fraction greater than 1 mm, the support fraction, 9, is then collected as a final product. The fraction smaller than 1 mm comprising substantially sand and rubber is discarded or separated further.

The enriched fraction, 3_1 and the large fraction, 3_2 are combined. The magnetic contaminants, f, possibly present in the fractions are removed by a magnet located after the fractions have been fused; Magnetic contaminants are discarded or reused.

After removal of the magnetic contaminants, the fused fractions are reduced in size by a cutting mill, D_1, to a size of approximately 8 mm. The cutting mill used in the example shown was a type H500 / R2-2000, available from Hosokawa Alpine AG, but can be obtained from other suppliers such as Amis MaschinenVertriebs GmbH, Zuzenhausen, Germany.

The reduced size fraction, fused, 3_3, which substantially comprises grass fiber component is then further enriched in a first separator E_1, which provides an air flow 20 configured to produce a swirling motion. In the example shown, the first separator, E_1, was a ZZS180 / 800 type air sweeping screen that can be obtained from Trenn- und Sortiertechnik GmbH in which the swirling movement is caused by the injection of an air flow, a, within zigzag channels within the classification channel. Air was provided at a frequency of 25 Hz. Other suppliers of zigzag sieves such as Hamos GmbH, Penzberg, Germany are available. The classification provides a lighter fraction, 10, which essentially comprises grass fiber components and a heavier fraction, 11, which comprises support moieties, sand and rubber.

The first heavier fraction, 11, can be discarded or separated further to increase yield.

The lighter fraction, 10, which essentially comprises grass fiber component is introduced with funnel into a second separator similar to the first separator, E_2, similar to the first separator but where the air was provided at a frequency of 20 Hz. The separation it provides a second lighter fraction, 12, which essentially comprises grass fiber components and a second heavier fraction, 13, which comprises a mixture of remaining support material, rubber and sand. The second heavier fraction, 13, can be discarded or separated further optionally combined with the first heavier fraction 35, 11.

The second lighter fraction, 12, is finally enriched in grass fiber components by sieving through a third sieve, S_3, which has a mesh size of 0.8 mm. The fraction having a length greater than 0.8 is collected as the grass fiber fraction, 14, completely purified while, the fraction less than 0.8, which comprises substantially sand, can be discarded or used as desired.

The essentially pure sand fraction, 7_1, the essentially pure rubber fraction, 8_1, the essentially pure support material fraction, 9 and the essentially pure grass fiber fraction, 14, are collected and used as starting material in a number of industries as detailed above.

Four. Five

Claims (10)

1. A method of separating a dry or dried synthetic turf product comprising at least one support material, a grass fiber component and additional components, said process comprising at least the consecutive stages of (a) reduce the size of the synthetic grass product to a grass material reduced in size; 5 (b) separating the grass material reduced in size by screening it to give at least a first fraction comprising substantially a mixture of support material and additional components and a second fraction comprising substantially grass fiber components; (c) separating the first fraction obtained in step (b) by specific weight using air to provide a low density fraction comprising substantially support material and a high density fraction comprising substantially additional components; (d) separating the second fraction obtained in step (b) by specific weight and size by providing an upward directed air flow in a separator configured to cause a swirling movement by means of which the lighter fraction is dragged up in the air flow and the heavy fraction is dropped down; wherein the lighter fraction substantially comprises grass fiber components and the heavy fraction substantially comprises a mixture of support material and additional components; Y (e) collect the low density fraction obtained in step (c) and the light fraction obtained in step (d). 2. A method according to claim 1, wherein the screening of step (b) is performed in a plurality of sieve assemblies and / or wherein the specific weight separation of step (c) is performed in a plurality of separation means and in which the separation of step (d) is performed in a plurality of sets of separators. 3. A method according to claim 1 or 2, wherein the additional components comprise a filler and wherein the first fraction obtained in step (b) before step (c) is subjected to an intermediate screening step (i) to provide a third fraction comprising substantially support material and a fourth fraction comprising substantially filler and in which the third fraction comprising substantially support material is further processed in step (c) and the fraction comprising substantially Stuffing is recovered. 4. A method according to claim 3, wherein the filler material comprises sand 30 and / or rubber and wherein the fourth fraction is subjected to the additional step (f) of specific gravity separation to provide a low fraction density comprising substantially rubber and a high density fraction comprising substantially sand. 5. A method according to any of claims 3 or 4, wherein the intermediate separation step (i) is performed on a sieve comprising a plurality of sieves, wherein at least one first sieve has a mesh size 3 mm and at least a second sieve has a mesh size of 0.8 mm; said separation provides a large fraction where the length of the largest dimension of the material reduced in size is 3 mm or more, said fraction comprising substantially grass fiber components; an intermediate fraction in which the length of the largest dimension of the material reduced in size is in the range of 0.8 to 3 mm and said intermediate fraction essentially comprises support material and a small fraction in which the length of the largest dimension is 0.8 mm or less, said substantially filled small fraction. 6. A method according to any of the preceding claims, wherein the second fraction obtained in step (b) is further reduced in size before being separated by air scanning in step (d), for example in A cutting mill. 7. A method according to claim 6, wherein the fraction further reduced in size has a length of the dimension greater than no more than about 10 mm, preferably not more than 8 mm. fifty A method according to any one of the preceding claims, wherein the separation of step (d) is performed in a cyclone separator or a zig-zag air sweep sieve. 9. A method according to claim 8, wherein the separation is carried out in a zig-zag air sieve sieve and the air is provided at a frequency of 18-27 Hz, more preferably 20-25 Hz. 10. A method according to claim 8 or 9, wherein the separation of stage (d) is carried out in two stages, wherein the air frequency of the first stage is greater than the frequency in the second stage, more preferably about 25 Hz in the first stage and about 20 Hz in the second stage.